[From Dag Forssell (950601 1045)]
Added literature references:
Joel Judd dissertation,
Powers BYTE articles.
Reformatted references per Gary's taste.
Updated WWW info per Gary's instructions.
···
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INTRODUCTION TO PERCEPTUAL CONTROL THEORY (PCT)
THE CONTROL SYSTEMS GROUP (CSG)
AND THE CONTROL SYSTEMS GROUP NETWORK (CSG-L or CSGnet)
Prepared by Dag Forssell with Gary Cziko
Updated June 1, 1995
This is an introduction to Perceptual Control Theory (PCT), and the
discussion group CSG-L. CSG-L is listed os Usenet as the newsgroup
"bit.sci.purposive-behavior." This introduction is posted at the
beginning of each month for newcomers to CSG-L and the newsgroup.
A complementary, more detailed "PCT Introduction and Resource
Guide" is available from the WWW server shown below (file
RESOURCE.PCT, 75 KB), or by mail (20 pages) as shown in the section
on references and order forms. It features the book jacket for
_Behavior: The Control of Perception_; two short essays by Bill
Powers: _An essay on the obvious_ and _Things I'd like to say if
they wouldn't think I am a nut_, which deal with the requirements
of developing psychology as physical science; the foreword for
_Living Control Systems II_ by Tom Bourbon and more; plus more
detailed descriptions of PCT books, videos, order forms etc.
This introduction provides information about:
Perceptual Control Theory (PCT): What it is
Introductions to Perceptual Control Theory
The Evolution of the Control Paradigm
Demonstrating the Phenomenon of Control
The Purpose of CSGnet
CSGnet Participants
Asking Questions
Post Format
The Control Systems Group
Accessing and Subscribing to CSGnet
Gopher and World-Wide Web
References
Order Forms
PERCEPTUAL CONTROL THEORY (PCT): WHAT IT IS
PCT offers a clear explanation for the pervasive phenomenon of
control, which is also known as purposeful behavior. Hierarchical
PCT (HPCT) outlines a hierarchical arrangement as a likely
organization of multiple control systems, which can explain the
purposeful behavior of living organisms.
PCT and HPCT were developed by William T. Powers, and introduced in
his 1973 book _Behavior: The Control of Perception_. (See
references and order forms, below). Powers shows us that the
engineering concept of control helps improve our understanding of
behavior, conflict, cooperation, and personal relationships. Just
as the in-depth explanatory theories of modern physical science
have helped us understand inanimate objects better than was
possible with experience and descriptive theories alone, the
in-depth explanations of PCT help us understand living organisms
better than has been possible with experience and descriptive
theories.
PCT focuses on how we look at and experience things, and the way
these perceptions are compared with experiences we want. The
difference produces action and physiology. Thus PCT explains how
thoughts become actions, feelings and results, and its principles
can be applied to any activity involving human experience.
PCT helps us understand people as they naturally are, just as
engineers understand physical phenomena as they naturally are. PCT
is remarkably simple, but like any other applied science, it
requires an understanding of basic principles and practice in their
application.
Much of the discussion on CSG-L reflects the rigorous "engineering
science" discipline of PCT and HPCT. Those who apply PCT and HPCT
to issues of personal relationships, education and management are
applying the basic principles to areas where they have not yet been
proven with scientific rigor, but seem to work well indeed.
INTRODUCTIONS TO PERCEPTUAL CONTROL THEORY
Here are introductions by Bill and Mary Powers:
* * * * * * * *
There have been two paradigms in the behavioral sciences since
the 1600's. One was the idea that events impinging on organisms
make them behave as they do. The other, which was developed in
the 1930's, is PERCEPTUAL CONTROL THEORY (PCT). Perceptual
Control Theory explains how organisms control what happens to
them. This means all organisms from the amoeba to humankind. It
explains why one organism can't control another without
physical violence. It explains why people deprived of any major
part of their ability to control soon become dysfunctional,
lose interest in life, pine away and die. It explains what a
goal is, how goals relate to action, how action affects
perceptions and how perceptions define the reality in which we
live and move and have our being. Perceptual Control Theory is
the first scientific theory that can handle all these phenomena
within a single, testable concept of how living systems work.
William T. Powers, November 3, 1991
* * * * * * * *
While the existence of control mechanisms and processes (such
as feedback) in living systems is generally recognized, the
implications of control organization go far beyond what is
generally accepted. We believe that a fundamental
characteristic of organisms is their ability to control; that
they are, in fact, living control systems. To distinguish this
approach from others using some version of control theory but
forcing it to fit conventional approaches, we call ours
Perceptual Control Theory, or PCT.
PCT requires a major shift in thinking from the traditional
approach: that what is controlled is not behavior, but
perception. Modelling behavior as a dependent variable, as a
response to stimuli, provides no explanation for the phenomenon
of achieving consistent ends through varying means, and
requires an extensive use of statistics to achieve modest (to
the point of meaningless) correlations. Attempts to model
behavior as planned and computed output can be demonstrated to
require levels of precise calculation that are unobtainable in
a physical system, and impossible in a real environment that is
changing from one moment to the next. The PCT model views
behavior as the means by which a perceived state of affairs is
brought to and maintained at a reference state. This approach
provides a physically plausible explanation for the consistency
of outcomes and the variability of means.
The PCT model has been used to simulate phenomena as diverse as
bacterial chemotaxis, tracking a target, and behavior in
crowds. In its elaborated form, a hierarchy of perceptual
control systems (HPCT), it has lent itself to a computer
simulation of tracking, including learning to track, and to new
approaches to education, management, and psychotherapy.
Control systems are not new in the life sciences. However,
numerous misapprehensions exist, passed down from what was
learned about control theory by non-engineers 40 or 50 years
ago without further reference to newer developments or
correction of initial misunderstandings. References in the
literature to the desirability of positive feedback and the
assertion that systems with feedback are slower than S-R
systems are simply false, and concerns about stability are
unfounded.
The primary barrier to the adoption of PCT concepts is the
belief--or hope--that control theory can simply be absorbed
into the mainstream life sciences without disturbing the status
quo. It is very hard to believe that one's training and life
work, and that of one's mentors, and their mentors, must be
fundamentally revised. Therefore, PCT appeals to those who feel
some dissatisfaction with the status quo, or who are attracted
to the idea of a generative model with broad application
throughout the life sciences (plus AI and robotics). There are
very few people working in PCT research. Much of its promise is
still simply promise, and it meets resistance from all sides.
It is frustrating but also tremendously exciting to be a part
of the group who believe that they are participating in the
birth of a true science of life.
Mary Powers, November 1992
* * * * * * * *
THE EVOLUTION OF THE CONTROL PARADIGM
The PCT paradigm originates in 1927, when an engineer named Harold
Black completed the technical analysis of closed loop control
systems. He was working with the negative feedback amplifier, which
is a control device. This led to a new engineering discipline and
the development of many purposeful machines. Purposeful machines
have built-in intent to achieve specified ends by variable means
under changing conditions.
The explanation for the phenomenon of control is the first
alternative to the linear cause-effect perspective ever proposed in
any science.
The first discussion of purposeful machines and people came in 1943
in a paper called: Behavior, Purpose and Teleology by Rosenblueth,
Wiener and Bigelow. This paper also argued that purpose belongs in
science as a real phenomenon in the present. Purpose does not mean
that somehow the future influences the present.
William T. (Bill) Powers developed PCT, beginning in the mid-50's.
In 1973 his book called "Behavior: the Control of Perception."
(often referred to as B:CP) was published. It is still the major
reference for PCT and discussion on CSG-L.
B:CP spells out a suggestion for a working model of how the human
brain and nervous system works. Our brain is a system that controls
its own perceptions. This view suggests explanations for many
previously mysterious aspects of how people interact with their
world.
Perceptual Control Theory has been accepted by independently
thinking psychologists, scientists, engineers and others. The
result is that an association has been formed (the Control System
Group), several books published, this CSGnet set up and that
several professors teach PCT in American universities today.
DEMONSTRATING THE PHENOMENON OF CONTROL
Few scientists recognize or understand the phenomenon of control.
It is not well understood in important aspects even by many control
engineers. Yet the phenomenon of control, when it is recognized and
understood, provides a powerful enhancement to scientific
perspectives.
It is essential to recognize that control exists and deserves an
explanation before any of the discourse on CSGnet will make sense.
Please download the introductory computer demonstrations,
simulations and tutorials, beginning with "demo1". See "Gopher and
World-Wide Web" below for obtaining files via FTP, Gopher, and WWW.
THE PURPOSE OF CSGnet
CSGnet provides a forum for development, use and testing of PCT.
CSGnet PARTICIPANTS
Many interests and backgrounds are represented here. Psychology,
Sociology, Linguistics, Artificial Intelligence, Robotics, Social
Work, Neurology, Modeling and Testing. All are represented and
discussed. As of March 20, 1995 there were 146 individuals from 20
countries subscribed to CSGnet.
ASKING QUESTIONS
Please introduce yourself with a statement of your professional
interests and background. It will help someone answer if you spell
out which demonstrations, introductory papers and references you
have taken the time to digest.
POST FORMAT
When you are ready to introduce yourself and post to CSG-L, please
begin each post with your name and date of posting at the beginning
of the message itself, as shown here:
[Dag Forssell (950212 1600)]
This lets readers know who sent the message, and when (sometimes
very different from the automated datestamp). It provides a
convenient reference for replies. When you respond to a message,
please use this reference and quote only relevant parts of the
message you comment on.
THE CONTROL SYSTEMS GROUP
The CSG is an organization of people in the behavioral, social, and
life sciences who see the potential in PCT for increased
understanding in their own fields and for the unification of
diverse and fragmented specialties.
Annual dues are $20 for full members and $5 for students.
The eleventh North American annual meeting of the CSG will held in
Durango, Colorado, on the campus of Fort Lewis College. It will be
held 19-23 July 1995. There will be 7 plenary meetings (mornings
and evenings), with afternoons, mealtimes, and late night free for
further discussion or recreation. Full details will be available on
CSGnet or by mail after April 1, 1995. The second meeting of the
European Control Systems Group (ECSG) will be held in 1996. Details
to be arranged and posted on this net.
For membership information write:
CSG, c/o Mary Powers, 73 Ridge Place CR 510, Durango, CO 81301-8136
USA or send e-mail to powers_w@fortlewis.edu.
ACCESSING AND SUBSCRIBING TO CSGnet
CSGnet can also be accessed via Usenet where it is listed as the
newsgroup "bit.sci.purposive-behavior" (NOTE: You may have to set
your default news server to news.cso.uiuc.edu to read this group.)
To subscribe to the listserv version of CSGnet, and learn about
options & commands, subscribers and archives, send a message to
listserv@vmd.cso.uiuc.edu
Message: (Comments: Not part of your message)
Subscribe CSG-L Firstname Lastname Institution (Your OWN name)
help (Basic introduction to commands)
info refcard (Comprehensive reference of commands)
set CSG-L digest (All CSG-L mail delivered once a day)
set CSG-L retro (Get copy of your own postings)
set CSG-L ack (Receive acknowledgements when posting)
query CSG-L (Your mail status & options)
review CSG-L countries (Subsribers & addresses, by country)
index CSG-L (List of archive files available to you)
get CSG-L LOG9502B (Get archive for second week of Feb 1995
--shown here as an example only).
The Bitnet address for the list server is listserv@uiucvmd.
To remove yourself from the subscribe to the listserv version of
CSGnet, send a message as follows to listserv@vmd.cso.uiuc.edu
Unsub CSG-L
For the "unsub" command to work, the command must be sent with the
same return address used for the original "subscribe" command.
Messages to the entire CSGnet community should be addressed to
CSG-L@vmd.cso.uiuc.edu
For more information about accessing CSGnet, contact Gary Cziko,
the network manager, at g-cziko@uiuc.edu
GOPHER AND WORLD-WIDE WEB
A number of documents as well as MS-DOS and Mackintosh computer
programs can be obtained via Gopher and the World-Wide Web
(currently under construction).
To use a Gopher browser, connect to gopher.ed.uiuc.edu and follow
the path:
Higher Education Resources/
Professional societies & journals/
Control Systems Group
or from your favorite Gopher server follow the path:
Other Gopher and Information Servers/
North America/
USA/
illinois/
University of Ill.--College of Education/
Higher Education Resources/
Professional societies & journals/
Control Systems Group
The WWW address for the CSG homepage (under construction) is
http://www.ed.uiuc.edu/csg/. We are currently experimenting with
providing archives of CSGnet discussions via WWW. You can also
access the CSG Gopher server from the WWW homepage.
REFERENCES
Here are some selected books, papers and computer programs on
Perceptual Control Theory. For a very complete list of CSG-related
publications, get the file biblio.pct from the fileserver as
described above. See also the _PCT Introduction and Resource
Guide_ and order forms below.
* * * * * * * *
Bourbon, WT, KE Copeland, VR Dyer, WK Harman & BL Mosely (1990). On
the accuracy and reliability of predictions by control-system
theory. Perceptual and Motor Skills, vol 71, 1990, 1331-1338.
The first of a 20-year series demonstrating the long-term
reliability and stability of predictions generated by the PCT
model.
Bourbon, W. Tom (In Press). Perceptual Control Theory. In: HL
Roitblat & J-A Meyer (eds.). Comparative approaches to cognitive
science. Cambridge, MA: MIT Press.
Chapter surveys applications of PCT modeling by Bill Powers and
Greg Williams (pointing, from the ARM/LITTLE MAN program); by
Rick Marken and Bill Powers (movement "up a gradient" by E.
coli), by Bill Powers, Clark Mcphail and Chuck Tucker (social
movement and static formations, from the GATHERINGS program),
and by Bourbon (tracking). The PCT model is contrasted with
some of the mainstream models and theories presented at the
workshop.
Cziko, Gary A. (1992). Purposeful behavior as the control of
perception: Implications for educational research. EDUCATIONAL
RESEARCHER, 21(9), 10-18, 27.
Introduction to PCT and implications for educational research.
Cziko, Gary A. (1992). Perceptual control theory: One threat to
educational research not (yet?) faced by Amundson, Serlin, and
Lehrer. EDUCATIONAL RESEARCHER, 21(9), 25-27.
Response to critics of previous article.
Ford, Edward E. (1989). FREEDOM FROM STRESS. Scottsdale AZ: Brandt
Publishing. A self-help book.
PCT in a counseling framework.
Ford, Edward E. (1987). LOVE GUARANTEED; A BETTER MARRIAGE IN 8
WEEKS. Scottsdale AZ: Brandt Publishing.
Ford, Edward E. (1994). DISCIPLINE FOR HOME AND SCHOOL. Scottsdale
AZ: Brandt Publishing.
Teaches school personnel and parents how to deal effectively
with children.
Forssell, Dag C., (1993). "Perceptual Control: A New Management
Insight." In ENGINEERING MANAGEMENT JOURNAL, 5(4), 17-25.
Forssell, Dag C., (1994). "Perceptual Control: Management Insight
for Problem Solving." In ENGINEERING MANAGEMENT JOURNAL, 6(3),
31-39.
Forssell, Dag C., (1995). "Perceptual Control: Leading
Uncontrollable People." In ENGINEERING MANAGEMENT JOURNAL, 7(1).
Forssell, Dag C., (1994). MANAGEMENT AND LEADERSHIP: INSIGHT FOR
EFFECTIVE PRACTICE.
A collection of articles (shown above) and working papers in
book form introducing and applying PCT in the context of
business and industry.
Forssell, Dag C. (Ed.), (1995). PCTDEMOS and PCTTEXTS. Two DOS
disks 1.44 MB 3 1/2". May be freely copied. Also available at the
WWW site shown above.
PCTdemos holds eight different tutorial, simulation and
demonstration programs with documentation. PCTtexts holds 3+
MB of essays, explanation, and debate.
Gibbons, Hugh. (1990). THE DEATH OF JEFFREY STAPLETON: EXPLORING
THE WAY LAWYERS THINK. Concord, NH: Franklin Pierce Law Center.
A text for law students using control theory.
Hershberger, Wayne. (Ed.). (1989). VOLITIONAL ACTION: CONATION AND
CONTROL (Advances in Psychology No. 62). NY: North-Holland.
16 of 25 articles on or about PCT.
Judd, Joel. (1992). SECOND LANGUAGE ACQUISITION AS THE CONTROL OF
NONPRIMARY LINGUISTIC PERCEPTION: A CRITIQUE OF RESEARCH AND
THEORY. Unpublished doctoral dissertation, University of Illinois
at Champaign-Urbana. _Dissertation Abstracts International_, _53_,
(7), #9236495.
Marken, Richard S. (Ed.). (1990). Purposeful Behavior: The control
theory approach. AMERICAN BEHAVIORAL SCIENTIST, 34(1). (Thousand
Oaks, CA: Sage Publications).
11 articles on control theory.
Marken, Richard S. (1992). MIND READINGS: EXPERIMENTAL STUDIES OF
PURPOSE. NC: New View.
Research papers exploring control.
McClelland, Kent. 1994. "Perceptual Control and Social Power".
SOCIOLOGICAL PERSPECTIVES 37(4):461-496.
McClelland, Kent. "On Cooperatively Controlled Perceptions and
Social order". Available from the author, Dept. of Sociology,
Grinnell College, Grinnell IOWA 50112 USA.
McPhail, Clark. (1990). THE MYTH OF THE MADDING CROWD. New York:
Aldine de Gruyter.
Introduces control theory to explain group behavior.
McPhail, Clark., Powers, William T., & Tucker, Charles W. (1992).
Simulating individual and collective action In temporary
gatherings. SOCIAL SCIENCE COMPUTER REVIEW, 10(1), 1-28.
Computer simulation of control systems in groups.
Petrie, Hugh G. (1981). THE DILEMMA OF INQUIRY AND LEARNING.
Chicago: University of Chicago Press.
Powers, William T. (1973). BEHAVIOR: THE CONTROL OF PERCEPTION.
Hawthorne, NY: Aldine DeGruyter.
The basic text.
Powers, William T. (1989). LIVING CONTROL SYSTEMS: SELECTED PAPERS.
NC: New View.
Previously published papers, 1960-1988.
Powers, William T. (1992). LIVING CONTROL SYSTEMS II: SELECTED
PAPERS. NC: New View.
Previously unpublished papers, 1959-1990
Powers, William T., THE NATURE OF ROBOTS:
1 DEFINING BEHAVIOR BYTE 4(6), June 1979, p132-144, 7 pages.
2 SIMULATED CONTROL SYSTEM, BYTE 4(7), July, 134-152, 12p.
3 A CLOSER LOOK AT HUMAN BEHAVIOR, BYTE 4(8), Aug, 94-116, 16p.
4 LOOKING FOR CONTROLLED VARIABLES, BYTE 4(8), Sep 96-112, 13p.
Richardson, George P. (1991). FEEDBACK THOUGHT IN SOCIAL SCIENCE
AND SYSTEMS THEORY. Philadelphia: University of Pennsylvania Press.
A review of systems thinking, including PCT.
Robertson, Richard J. and Powers, William T. (Eds.). (1990).
INTRODUCTION TO MODERN PSYCHOLOGY: THE CONTROL THEORY VIEW. NC: New
View.
College-level text.
Runkel, Philip J. (1990). CASTING NETS AND TESTING SPECIMENS. New
York: Praeger.
When statistics are appropriate; when models are required.
* * * * * * * *
ORDER FORMS
A free 20 page PCT Resource Guide with introductions and more
detail on the references listed above and a few more --
publishers, books, articles, videos, seminars, and the DOS
demonstration disk -- may be obtained by sending a note with
1) a self addressed, stamped (55 cents) envelope, or
2) two "international reply" coupons
- every post office in the world sells them.
to: PCT Introduction and Resource Guide
Dag Forssell
23903 Via Flamenco
Valencia, California, 91355-2808 USA.
The PCT Introduction and Resource Guide is also available in ASCII
format from the WWW site shown above.
Order forms in the Guide are reproduced below without descriptions.
All prices current as of April, 1995.
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